The prior art includes stoves with feed systems for metering particulate fuel from a hopper to a firebox. These systems include reciprocal pushers, rotating cups and augers for moving the fuel.
The fuel feed system in a particulate fuel fired stove must prevent burnback, which is the combustion of fuel backwards from the firebox and into the hopper. Burnback is commonly caused when the forced air draft is turned off and burning fuel induces a draft through the hopper and feed system. This draft supplies oxygen to support burnback. The problem is particularly acute with a readily combustible fuel such as wood chips or pellets, walnut shells, peach pits or shelled corn.
Conventional fuel systems prevent burnback in coal fired stoves. These systems include hoppers with oscillating gates, intermittent feed augers and fuel conveyors with burnback barriers. Such systems are relatively complicated and expensive and unsuited for smaller stoves burning highly combustible fuels.
While double auger and rotating cup feeders have been used for wood pellet stoves and are acceptable, they involve extra expense and extra moving parts. The feed rate of rotating cup feeders is difficult to adjust as it requires replacing or removing one or more of the cups.